Scaled-energy spectroscopy of helium|M|=1Rydberg atoms in a static electric field

Abstract

We present scaled-energy spectra on helium Rydberg atoms in a static electric field. ͉M ͉ϭ1 states were studied in excitation from the 2 1 S 0 metastable state. Spectra were recorded for ⑀ϭϪ2.940(4), ⑀ϭ Ϫ2.350(4), both below the saddle point, and ⑀ϭϪ1.760(4), above the saddle point. Closed-orbit theory was applied to interpret the spectra. A recent extension to closed-orbit theory, incorporating core effects, was used. This significantly improved agreement between experiment and theory. ͓S1050-2947͑98͒02610-9͔

Photoabsorption spectra of the diamagnetic hydrogen atom in the transition regime to chaos: closed orbit theory with bifurcating orbits

“…The scenario for x < 0 is similar, the difference being that all stationary points and corresponding closed orbits are real in region C. This scenario has been observed at scaled energiesẼ > −0.418 [33]. The stationary values of the normal form Φ(t) in equation (14) and the second derivative Φ ′′ (t) as functions of the unfolding parameter y are presented in figure 6. Evidently, figure 6 qualitatively agrees with the closed orbit parameters ∆S andm 12 shown in figure 3.…”

“…with the coefficients u and v chosen such that ϑ(t) maps the stationary points of the normal form (14) onto the numerically determined angles ϑ i and ϑ f . (Note that ϑ i = ϑ f or ϑ i = π − ϑ f for all orbits involved.)…”

“…Characterization of the stationary points of the normal form Φ(t) in equation(14). The functions y = 0 and y = x 2 /3 divide the (x, y)-plane into different domains.…”

Closed-orbit recurrences in molecular hydrogen

“…The theoretical basis for the advancement of COT, which describes atomic dynamics utilizing the concepts of trajectory and orbits, occurred earlier with the full development of periodic orbit theory by Gutzwiller in 1971 [3]. During the last decade COT has been modified and applied to nonhydrogenic atoms [4][5][6][7] resulting in very good agreement with many Stark SERS experimental studies including those in sodium [1,8], lithium [9,10], barium [11][12][13], calcium [13], helium [14][15][16][17][18], argon [19,20], and strontium [21]. This is also true for other experiments employing SERS with magnetic fields [22][23][24].…”

Geometry and topology of escape. I. Epistrophes

“…However, in most experiments on excited atoms in strong fields, the initial distribution is quite different. The electron attains a high energy by single-photon excitation from a localized strongly-bound initial state [17,18,19,20,21,22]. The trajectories therefore start close to the nucleus and go out in all directions.…”